A newer version of this document is available. Customers should click here to go to the newest version.
Visible to Intel only — GUID: GUID-9C855565-71F6-4BEC-A1A4-C2D39090C4C7
Visible to Intel only — GUID: GUID-9C855565-71F6-4BEC-A1A4-C2D39090C4C7
getrsnp_batch (Buffer Strided Version)
Solves a batch of linear equations with an LU-factored square coefficient matrices, with multiple right-hand sides. This routine belongs to the oneapi::mkl::lapack namespace.
Description
The routine solves for Xi the following systems of linear equations:
Ai * Xi = Bi If trans = mkl::transpose::notrans
AiT * Xi = Bi If trans = mkl::transpose::trans
AiH * Xi = Bi If trans = mkl::transpose::conjtrans
Before calling this routine you must call getrfnp_batch (Buffer Strided Version) (without pivoting) to compute the LU factorization of Ai.
API
Syntax
namespace oneapi::mkl::lapack { void getrsnp_batch(sycl::queue &queue, mkl::transpose trans, int64_t n, int64_t nrhs, sycl::buffer<T> &a, int64_t lda, int64_t stride_a, sycl::buffer<T> &b, int64_t ldb, int64_t stride_b, int64_t batch_size, sycl::buffer<T> &scratchpad, int64_t scratchpad_size) }
This function supports the following precisions and devices:
T |
Devices supported |
|---|---|
float |
CPU and GPU |
double |
CPU and GPU |
std::complex<float> |
CPU and GPU |
std::complex<double> |
CPU and GPU |
Input Parameters
- queue
-
Device queue where calculations will be performed.
- trans
-
Indicates the form of the equations:
If trans = mkl::transpose::nontrans, then Ai*Xi = Bi is solved for Xi.
If trans = mkl::transpose::trans, then AiT*Xi = Bi is solved for Xi.
If trans = mkl::transpose::conjtrans, then AiH*Xi = Bi is solved for Xi.
- n
-
The order of the matrices Ai and the number of rows in matrices Bi (n ≥ 0).
- nrhs
-
The number of right hand sides (nrhs ≥ 0).
- a
-
Array containing the factorizations of the matrices Ai, as returned by getrfnp_batch (Buffer Strided Version).
- lda
-
The leading dimension of Ai (lda ≥ max(1, n)).
- stride_a
-
The stride between the beginnings of matrices Ai inside the batch array a (stride_a ≥ max(1, lda * n)).
- b
-
The array containing the matrices Bi whose columns are the right-hand sides for the systems of equations.
- ldb
-
The leading dimensions of Bi (ldb ≥ max(1, n)).
- stride_b
-
The stride between the beginnings of matrices Bi inside the batch array b (stride_b ≥ max(1, ldb * nrhs)).
- batch_size
-
The number of problems in a batch (batch_size ≥ 0).
- scratchpad
-
Scratchpad memory to be used by routine for storing intermediate results.
- scratchpad_size
-
Size of scratchpad memory as a number of floating point elements of type T. Size should not be less then the value returned by stride version of getrsnp_batch_scratchpad_size (Strided Version) function.
Output Parameters
- b
-
Overwritten by the solution matrices Xi.
Exceptions
Exception |
Description |
|---|---|
mkl::lapack::batch_exception |
This exception is thrown when problems occur during calculations. You can obtain the info code of the problem using the info() method of the exception object: If info = -n, the n-th parameter had an illegal value. If info equals the value passed as scratchpad size, and detail() returns non-zero, then the passed scratchpad is of insufficient size, and the required size should be not less then value returned by the detail() method of the exception object. If info is zero, then the diagonal element of some of Ui is zero, and the solve could not be completed. The indexes of such matrices in the batch can be obtained with the ids() method of the exception object. You can obtain the indexes of the first zero diagonal elements in these Ui matrices using the infos() method of the exception object. |